site/node_modules/css-tree/lib/generator/token-before.js

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2024-10-14 06:09:33 +00:00
import {
WhiteSpace,
Delim,
Ident,
Function as FunctionToken,
Url,
BadUrl,
AtKeyword,
Hash,
Percentage,
Dimension,
Number as NumberToken,
String as StringToken,
Colon,
LeftParenthesis,
RightParenthesis,
CDC
} from '../tokenizer/index.js';
const PLUSSIGN = 0x002B; // U+002B PLUS SIGN (+)
const HYPHENMINUS = 0x002D; // U+002D HYPHEN-MINUS (-)
const code = (type, value) => {
if (type === Delim) {
type = value;
}
if (typeof type === 'string') {
const charCode = type.charCodeAt(0);
return charCode > 0x7F ? 0x8000 : charCode << 8;
}
return type;
};
// https://www.w3.org/TR/css-syntax-3/#serialization
// The only requirement for serialization is that it must "round-trip" with parsing,
// that is, parsing the stylesheet must produce the same data structures as parsing,
// serializing, and parsing again, except for consecutive <whitespace-token>s,
// which may be collapsed into a single token.
const specPairs = [
[Ident, Ident],
[Ident, FunctionToken],
[Ident, Url],
[Ident, BadUrl],
[Ident, '-'],
[Ident, NumberToken],
[Ident, Percentage],
[Ident, Dimension],
[Ident, CDC],
[Ident, LeftParenthesis],
[AtKeyword, Ident],
[AtKeyword, FunctionToken],
[AtKeyword, Url],
[AtKeyword, BadUrl],
[AtKeyword, '-'],
[AtKeyword, NumberToken],
[AtKeyword, Percentage],
[AtKeyword, Dimension],
[AtKeyword, CDC],
[Hash, Ident],
[Hash, FunctionToken],
[Hash, Url],
[Hash, BadUrl],
[Hash, '-'],
[Hash, NumberToken],
[Hash, Percentage],
[Hash, Dimension],
[Hash, CDC],
[Dimension, Ident],
[Dimension, FunctionToken],
[Dimension, Url],
[Dimension, BadUrl],
[Dimension, '-'],
[Dimension, NumberToken],
[Dimension, Percentage],
[Dimension, Dimension],
[Dimension, CDC],
['#', Ident],
['#', FunctionToken],
['#', Url],
['#', BadUrl],
['#', '-'],
['#', NumberToken],
['#', Percentage],
['#', Dimension],
['#', CDC], // https://github.com/w3c/csswg-drafts/pull/6874
['-', Ident],
['-', FunctionToken],
['-', Url],
['-', BadUrl],
['-', '-'],
['-', NumberToken],
['-', Percentage],
['-', Dimension],
['-', CDC], // https://github.com/w3c/csswg-drafts/pull/6874
[NumberToken, Ident],
[NumberToken, FunctionToken],
[NumberToken, Url],
[NumberToken, BadUrl],
[NumberToken, NumberToken],
[NumberToken, Percentage],
[NumberToken, Dimension],
[NumberToken, '%'],
[NumberToken, CDC], // https://github.com/w3c/csswg-drafts/pull/6874
['@', Ident],
['@', FunctionToken],
['@', Url],
['@', BadUrl],
['@', '-'],
['@', CDC], // https://github.com/w3c/csswg-drafts/pull/6874
['.', NumberToken],
['.', Percentage],
['.', Dimension],
['+', NumberToken],
['+', Percentage],
['+', Dimension],
['/', '*']
];
// validate with scripts/generate-safe
const safePairs = specPairs.concat([
[Ident, Hash],
[Dimension, Hash],
[Hash, Hash],
[AtKeyword, LeftParenthesis],
[AtKeyword, StringToken],
[AtKeyword, Colon],
[Percentage, Percentage],
[Percentage, Dimension],
[Percentage, FunctionToken],
[Percentage, '-'],
[RightParenthesis, Ident],
[RightParenthesis, FunctionToken],
[RightParenthesis, Percentage],
[RightParenthesis, Dimension],
[RightParenthesis, Hash],
[RightParenthesis, '-']
]);
function createMap(pairs) {
const isWhiteSpaceRequired = new Set(
pairs.map(([prev, next]) => (code(prev) << 16 | code(next)))
);
return function(prevCode, type, value) {
const nextCode = code(type, value);
const nextCharCode = value.charCodeAt(0);
const emitWs =
(nextCharCode === HYPHENMINUS &&
type !== Ident &&
type !== FunctionToken &&
type !== CDC) ||
(nextCharCode === PLUSSIGN)
? isWhiteSpaceRequired.has(prevCode << 16 | nextCharCode << 8)
: isWhiteSpaceRequired.has(prevCode << 16 | nextCode);
if (emitWs) {
this.emit(' ', WhiteSpace, true);
}
return nextCode;
};
}
export const spec = createMap(specPairs);
export const safe = createMap(safePairs);